Presently, there are on the market necklaces, bracelets, earrings and other ornamental objects created from a helicoidal spiral of a gold alloy, obtained through a manufacturing technology which originates a Model known by the operators of the gold industry as OMEGAS model (Italian Design No. 00072788 of Feb. 26, 1996 in the name of OROCINQUE S.p.A. of Arezzo).
In the OMEGAS model the helicoidal spiral is obtained from a “plate strip” or “ribbon” of gold alloy of adequate width and thickness, which is wrapped as a solenoid on a flat metal support which acts as a guide base to produce the spiral itself.
Through the resulting solenoid, deprived of its flat base, a weak support of precious metal is threaded, for example “milanaise mesh”, “braiding”, soft chain, or other supports capable to be deformed, so that the coupling is free, with the sliding support inside the spiral but without slack. Said composite structure undergoes a strong “stamping” process through which the anatomic shape and therefore the desired profile are obtained. The long element so realised is then transformed into necklaces, bracelets, earrings or other items, with the standard finishing operations. The objects produced through this process are made of yellow or white gold. In some cases, however, a bi-coloured product is required: yellow on one side and white on the other.
The two colours are now obtained starting only and exclusively from a plate strip or a wire of yellow gold alloy which are wrapped as a solenoid around the soft support, therefore, they are “stamped” to give them the required anatomic shape.
The stamping originates a two faced item; the faces can be both flat or one concave the other convex, or both convex. In order to give the product a bi-coloured aspect, one of the two sides undergoes a rhodium treatment through a galvanic bath, after the other side has been covered with a protective resin or paint that can be applied with a brush.
After the rhodium treatment, on the non-protected side, the protective paint or resin is removed with a solvent from the other side so the product has a yellow surface and a white rhodium plated one.
From the above description it is obvious that the “white” colour of one of the sides, which should be of white gold, is actually a simulation in that it is due to the rhodium treatment and not to the gold alloy.
When the ornament is worn, its use will wear out the very thin layer of rhodium and the yellow gold will reappear. The ornament in time will turn to a uniform yellow colour.
The so made ornaments have a lower value.